新型組蛋白去乙醯化酶抑制劑在骨髓纖維化中的治療潛力與作用機制

Abstract

骨髓纖維化（Myelofibrosis, MF）是一種骨髓增生性腫瘤（myeloproliferative neoplasm）。其特徵為骨髓基質的結構異常及網狀纖維與膠原纖維的過度沉積，導致骨髓微環境受損。由於受損骨髓中造血功能障礙，患者常出現貧血與因髓外造血所引起的肝脾腫大，進一步影響生活品質。此外，骨髓微環境的改變亦為惡性造血細胞提供有利的生存環境，使部分患者進一步演變為急性骨髓性白血病（acute myeloid leukemia, AML），大幅降低其存活率。目前的治療策略主要聚焦於緩解全身性症狀，但對於骨髓纖維化的抑制或逆轉效果有限。愈來愈多研究顯示，組蛋白去乙醯化酶（histone deacetylases, HDACs）可透過調控細胞骨架結構，並下調抗纖維化與促凋亡基因的表達，促進纖維化。此外，MF患者的HDAC表現量顯著高於健康個體，HDAC抑制劑（HDAC inhibitors, HDACis）被認為具有潛在的治療價值，可用以逆轉MF病理狀態。因此，本研究旨在探討一種新型HDAC抑制劑在MF治療中的潛力及其作用機制。我們使用小鼠骨髓來源的纖維母細胞樣基質細胞OP9與M2-10B4，使其在TGF-β刺激下，表現出增殖速率上升與膠原蛋白合成增加的現象，模擬纖維化狀態。結果顯示，此新型HDAC抑制劑cpd15可成功誘導組蛋白乙醯化及細胞凋亡、抑制膠原蛋白與細胞外基質形成。根據蛋白質體分析，cpd15能促進抗纖維化路徑及抑制促纖維化路徑表現，同時具有改善發炎微環境、增加細胞清除活性氧的能力，使其微環境不利於纖維化發展以發揮抗纖維化作用，顯示其具逆轉纖維化之潛力，為MF治療帶來新的契機。

Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by the alteration of the bone marrow stroma and the excessive accumulation of reticulin and collagen fibers, leading to impaired bone marrow microenvironment. Due to impaired hematopoiesis in the damaged bone marrow, patients develop anemia and extramedullary hematopoiesis–induced hepatosplenomegaly, ultimately compromising their quality of life. Moreover, the altered bone marrow microenvironment creates a more favorable niche for malignant hematopoietic cells, predisposing some patients to progression to acute myeloid leukemia (AML), which significantly reduces survival rates. Current therapeutic strategies primarily aim to alleviate systemic symptoms but fail to effectively target or reverse bone marrow fibrosis. Accumulating evidence suggests that histone deacetylases (HDACs) promote fibrotic processes by influencing cytoskeletal organization and downregulating anti-fibrotic and pro-apoptotic gene expression. Furthermore, MF patients exhibit significantly elevated HDAC expression levels compared to healthy individuals, suggesting that HDAC inhibitors (HDACis) may have the potential for reversing MF. Thus, this study aims to investigate the therapeutic potential and underlying mechanisms of a novel HDACi in MF treatment. Two murine bone marrow–derived fibroblast-like stroma cell lines, OP9 and M2-10B4, were used in this study. TGF-β was added to the culture medium to stimulate these cells, resulting in increased proliferative capacity and enhanced collagen synthesis, thereby establishing an in vitro model that recapitulates a fibrotic phenotype. Our results demonstrated that the novel HDAC inhibitor cpd15 effectively induced histone acetylation, promoted apoptosis, and suppressed the expression of collagen and extracellular matrix–associated genes. Proteomic analysis further revealed that cpd15 upregulated anti-fibrotic signaling pathways while concurrently downregulating pro-fibrotic pathways. In addition, cpd15 improved the inflammatory microenvironment and enhanced cellular reactive oxygen species (ROS) scavenging capacity, thereby creating a milieu unfavorable for fibrotic progression. Collectively, these findings suggest that cpd15 exerts anti-fibrotic effects and holds the potential to reverse fibrosis, providing a promising therapeutic strategy for MF.